Embodiments of the disclosure relate to an autofocus apparatus and method for a camera, and more particularly, to a camera controller using a gravity sensor and a temperature sensor, an autofocus method for a camera, and a system including the camera controller.
Autofocus is a function of automatically focusing on an object and provides faster and more accurate focusing than manual focus. A camera module supporting the autofocus usually includes an image sensor, a lens, and an actuator moving the lens. The actuator moves the lens in a direction perpendicular to the plane of a sensor so that the lens is in focus. Actuator types include a voice coil motor (VCM), a Piezo motor, and a stepper motor. A VCM actuator is usually used in low-middle priced mobile cameras.
Camera lenses are divided into glass lenses, plastic lenses, and liquid lenses according to materials. Low priced plastic lenses are usually used in mobile cameras. A plastic lens has a disadvantage of low heat resistance. In other words, the plastic lens greatly contracts and expands according to ambient temperature, thereby significantly changing a focal length.